The Levelwear Levelwear PM2.5 Mask Filters are sold in a pack of 10 filters and are to be used along with our Levelwear Guard 2 face mask covering and most other masks that allow for filters. PM2.5 is defined as "Particulate Matter that are 2.5 microns small" which tells you the size of the particles blocked completely by the filter. The coronavirus lipid is technically smaller than this, research tests show PM2.5 filters with a cloth mask will reduce airborne particulates by over 90%. The PM2.5 filters are made with Five layers of protection for superior safety.
10 Filters per package.
Each Filter is recommended for about 24 hours of use (about a week of occasional use).